| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hdfs.server.namenode; |
| |
| import java.io.DataInputStream; |
| import java.io.ByteArrayInputStream; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.hdfs.protocol.HdfsConstants; |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * An implementation of the abstract class {@link EditLogInputStream}, |
| * which is used to updates HDFS meta-data state on a backup node. |
| * |
| * @see org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol#journal |
| * (org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration, |
| * int, int, byte[]) |
| */ |
| class EditLogBackupInputStream extends EditLogInputStream { |
| final String address; // sender address |
| private final ByteBufferInputStream inner; |
| private DataInputStream in; |
| private FSEditLogOp.Reader reader = null; |
| private FSEditLogLoader.PositionTrackingInputStream tracker = null; |
| private int version = 0; |
| |
| /** |
| * A ByteArrayInputStream, which lets modify the underlying byte array. |
| */ |
| private static class ByteBufferInputStream extends ByteArrayInputStream { |
| ByteBufferInputStream() { |
| super(new byte[0]); |
| } |
| |
| void setData(byte[] newBytes) { |
| super.buf = newBytes; |
| super.count = newBytes == null ? 0 : newBytes.length; |
| super.mark = 0; |
| reset(); |
| } |
| |
| /** |
| * Number of bytes read from the stream so far. |
| */ |
| int length() { |
| return count; |
| } |
| } |
| |
| EditLogBackupInputStream(String name) throws IOException { |
| address = name; |
| inner = new ByteBufferInputStream(); |
| in = null; |
| reader = null; |
| } |
| |
| @Override |
| public String getName() { |
| return address; |
| } |
| |
| @Override |
| protected FSEditLogOp nextOp() throws IOException { |
| Preconditions.checkState(reader != null, |
| "Must call setBytes() before readOp()"); |
| return reader.readOp(false); |
| } |
| |
| @Override |
| protected FSEditLogOp nextValidOp() { |
| try { |
| return reader.readOp(true); |
| } catch (IOException e) { |
| throw new RuntimeException("got unexpected IOException " + e, e); |
| } |
| } |
| |
| @Override |
| public int getVersion(boolean verifyVersion) throws IOException { |
| return this.version; |
| } |
| |
| @Override |
| public long getPosition() { |
| return tracker.getPos(); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| in.close(); |
| } |
| |
| @Override |
| public long length() throws IOException { |
| // file size + size of both buffers |
| return inner.length(); |
| } |
| |
| void setBytes(byte[] newBytes, int version) throws IOException { |
| inner.setData(newBytes); |
| tracker = new FSEditLogLoader.PositionTrackingInputStream(inner); |
| in = new DataInputStream(tracker); |
| |
| this.version = version; |
| |
| reader = new FSEditLogOp.Reader(in, tracker, version); |
| } |
| |
| void clear() throws IOException { |
| setBytes(null, 0); |
| reader = null; |
| this.version = 0; |
| } |
| |
| @Override |
| public long getFirstTxId() { |
| return HdfsConstants.INVALID_TXID; |
| } |
| |
| @Override |
| public long getLastTxId() { |
| return HdfsConstants.INVALID_TXID; |
| } |
| |
| @Override |
| public boolean isInProgress() { |
| return true; |
| } |
| |
| @Override |
| public void setMaxOpSize(int maxOpSize) { |
| reader.setMaxOpSize(maxOpSize); |
| } |
| } |